drm/amdgpu: simplify allocation of scratch regs

The scratch regs are sequential so there's no need to keep
them in an array, we can just return the index of the first
free register + the base register. Also change the array
of bools for keeping track of the free regs to a bitfield.

Reviewed-by: Christian König <[email protected]>
Signed-off-by: Nils Wallménius <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index ffeda245f38ba24927e5a1bc59b958aa91664c77..953148058bdbaf8a7fce506cade4e5535caec822 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -794,8 +794,7 @@ struct amdgpu_kiq {
 struct amdgpu_scratch {
        unsigned                num_reg;
        uint32_t                reg_base;
-       bool                    free[32];
-       uint32_t                reg[32];
+       uint32_t                free_mask;
 };
 
 /*

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 01a42b6a69a4bb8b3b1653e57bf28da6cb5911e1..19943356cca778331220de2ccd5819caf471230c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -42,12 +42,12 @@ int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg)
 {
        int i;
 
-       for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-               if (adev->gfx.scratch.free[i]) {
-                       adev->gfx.scratch.free[i] = false;
-                       *reg = adev->gfx.scratch.reg[i];
-                       return 0;
-               }
+       i = ffs(adev->gfx.scratch.free_mask);
+       if (i != 0 && i <= adev->gfx.scratch.num_reg) {
+               i--;
+               adev->gfx.scratch.free_mask &= ~(1u << i);
+               *reg = adev->gfx.scratch.reg_base + i;
+               return 0;
        }
        return -EINVAL;
 }
@@ -62,14 +62,7 @@ int amdgpu_gfx_scratch_get(struct amdgpu_device *adev, uint32_t *reg)
  */
 void amdgpu_gfx_scratch_free(struct amdgpu_device *adev, uint32_t reg)
 {
-       int i;
-
-       for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-               if (adev->gfx.scratch.reg[i] == reg) {
-                       adev->gfx.scratch.free[i] = true;
-                       return;
-               }
-       }
+       adev->gfx.scratch.free_mask |= 1u << (reg - adev->gfx.scratch.reg_base);
 }
 
 /**

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
index b323f5ef64d217813683722ec4cd25282e9185ea..e0132436c76f7d69094a38935d9f580013e9321b 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
@@ -1794,14 +1794,9 @@ static void gfx_v6_0_gpu_init(struct amdgpu_device *adev)
 
 static void gfx_v6_0_scratch_init(struct amdgpu_device *adev)
 {
-       int i;
-
        adev->gfx.scratch.num_reg = 7;
        adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-       for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-               adev->gfx.scratch.free[i] = true;
-               adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-       }
+       adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 static int gfx_v6_0_ring_test_ring(struct amdgpu_ring *ring)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
index c4e14015ec5bece8aee8560d71c4e98d4ba4f9dd..cfed6db69b930f8456b4a1eb17ba7c8dc4f78a7f 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
@@ -2003,14 +2003,9 @@ static void gfx_v7_0_gpu_init(struct amdgpu_device *adev)
  */
 static void gfx_v7_0_scratch_init(struct amdgpu_device *adev)
 {
-       int i;
-
        adev->gfx.scratch.num_reg = 7;
        adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-       for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-               adev->gfx.scratch.free[i] = true;
-               adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-       }
+       adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 /**

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index c8c45ba952c825d3afb835867f6096b522e12d17..69543d4eef343aa7d80c178d5e957b4bb8235410 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -749,14 +749,9 @@ static void gfx_v8_0_init_golden_registers(struct amdgpu_device *adev)
 
 static void gfx_v8_0_scratch_init(struct amdgpu_device *adev)
 {
-       int i;
-
        adev->gfx.scratch.num_reg = 7;
        adev->gfx.scratch.reg_base = mmSCRATCH_REG0;
-       for (i = 0; i < adev->gfx.scratch.num_reg; i++) {
-               adev->gfx.scratch.free[i] = true;
-               adev->gfx.scratch.reg[i] = adev->gfx.scratch.reg_base + i;
-       }
+       adev->gfx.scratch.free_mask = (1u << adev->gfx.scratch.num_reg) - 1;
 }
 
 static int gfx_v8_0_ring_test_ring(struct amdgpu_ring *ring)